Mechanical Properties&colon;Ultrasonic Test&colon;Material will be ultrasonically tested at appropriate stages of the manufacture to ensure the quality&comma; as agreed between seller and purchaser&period;

Heat Treatment&colon;Hardness &colon;Annealed&lpar;&plus;A&rpar; max&colon; 269 BHNTool steel A7 when heat-treatment the preheat Temperature need reach 816°C&comma; and the temperature may be ± 14 °C &period;Tool steel A7 when austenitizing &comma;should keep 5-15 minutes long&period; If is the salt bath &comma;temperature should keep in the 954 °C&comma; and shall be ± 5&period;6 °C&period; Or is the controlled atmosphere furnaces&comma; temperature should keep in the 968 °C&comma; and shall be ± 5&period;6 °C&period;